Fixing agent is an auxiliary agent used to improve the color fastness of dyes on fabrics. As a post-finishing auxiliary, it can combine with the free ion water-soluble groups of dyes to form insoluble colored substances. Chemicalbook improves the washing and perspiration fastness of colors, reduces the hydrophilicity of dyes, and effectively improves the dyeing properties of dyes. Fixation rate, washing resistance, rubbing fastness and dye utilization rate, and sometimes can also improve its light fastness.